Huge strides have been made in understanding how different diseases cause damage in the brain and so produce dementia. And with increased funding over the past few years, there are now many more research studies and clinical trials taking place.

Although a cure may be some years away, there are some very promising advances.

Here are some of the areas researchers are working on and their findings so far.

Stem cells and dementia

Stem cells are "building block" cells. They can develop into many different cell types, including brain or nerve cells.

Scientists have taken skin cells from people with certain types of dementia, such as Alzheimer’s disease, and "reprogrammed" them into stem cells in the lab. They've then triggered these stem cells to become brain cells.

By studying these cells, scientists have gained important insights into how the damage to the brain begins and how it might be halted.

These brain cells can also be used to test potential treatments at a very early stage.

Immunotherapy

Immunotherapy involves boosting the body’s own defences to fight disease. It's one of the approaches that has been very effective in other diseases such as cancer.

In dementia, some studies have used vaccination against abnormal proteins that build up in the brain in Alzheimer's disease. Other studies have used monoclonal antibodies (man-made versions of immune system proteins) to target these proteins to slow the disease.

For example, monoclonal antibodies have been designed to target the amyloid protein, which builds up in the brains of people with Alzheimer's disease.

Most studies involving vaccination or monoclonal antibodies targeting amyloid have so far been unsuccessful. However, lessons have been learnt from these failed studies and a number of clinical trials are taking place, including a trial of the monoclonal antibody aducanumab.

The initial results from an early-phase clinical trial of this drug were promising. Aducanumab appeared to reduce the build-up of amyloid in people with early Alzheimer's disease, leading to a slower decline in memory and thinking skills.

Identifying who's at risk of dementia

Experts know that damage to the brain caused by Alzheimer's disease can start many years before symptoms appear. If people at risk of Alzheimer's could be identified at an early stage, it is hoped that treatments could be offered that would slow down or even stop the disease.

A major study, called PREVENT, concentrates on people in their 40s and 50s to identify those who are at greater risk of developing Alzheimer's (based on family history and genetics). It aims to understand what is happening in their brains before symptoms appear.

Specialised brain scans, known as PET scans, have been developed to study two proteins (amyloid and tau) in the brains of those with Alzheimer’s disease. The aim is to increase the understanding of the disease process, and also to identify those people who will benefit most from new drug treatments.

Although PET scans are sometimes used to help with a dementia diagnosis, these highly specialised scans are usually only available as part of clinical trials.

A number of different trials are now under way in people who are currently well but are at increased risk of Alzheimer's disease.

Prevention is important

Even if we find an effective cure for dementia, it would be better to try to prevent it ocurring in the first place.

Research has shown that the risk factors for heart disease and stroke – such as raised blood pressure, diabetes, obesity and smoking – are also risk factors for dementia. By modifying or changing these risk factors in mid-life, the risk of dementia could be reduced by up to 30%.